3 ms·

> The long wavelength of the microwave requires a long antenna, and allows power to be beamed through the Earth’s atmosphere, rain or shine, at safe, low intens

by elihu 6y ago

> The long wavelength of the microwave requires a long antenna, and allows power to be beamed through the Earth’s atmosphere, rain or shine, at safe, low intensity levels hardly stronger than the midday sun. Birds and planes wouldn’t notice much of anything flying across their paths. It doesn't look like they mention a specific wavelength in the article, but the reference to "long wavelength" and "long antenna" seems to imply frequencies much lower than what I'd consider microwave. Generally, the lower the frequency is, the less harm it causes to living things. Though I either way I wouldn't want to live right next to the ground station. I suppose it would be similar to living right next to a radio transmission tower or a radar station.

willis936 6y ago
I generally expect sub 100 MHz to be called radio rather than microwave, but I shouldn’t make assumptions. So you need a quarter wave to be longer than a building to make it not a concern, practically it needs to be much longer if you’re sending serious power and want to keep the density down. Let’s aim for a 1 km long antenna in space with voltage high enough that ohmic losses are not a concern, or a very large superconducting antenna and all of the apparatus that goes with it. Millions of volts likes to arc when you have debris just floating around everywhere in space. Superconducting is much more attractive regardless of the extra apparatus. I don’t see many points of concern, though you could still damage infrastructure if you aren’t constantly aligned. Blowing up terrestrial grids isn’t as bad as cooking people alive. It would still be the most dangerous thing we've ever put in space by a pretty wide margin. Keep space filled exclusively with small tin cans is not an accident and not entirely due to technical or economic limitations. It is a very sensitive political area. Putting anything that could be dangerous in orbit makes it dangerous to everyone. So your adversary across the ocean blows up a reactor? Cool. As long as they don't blow me up.
- elihu 6y ago
  > It would still be the most dangerous thing we've ever put in space by a pretty wide margin. I don't know about that. We set off a 1.4 megaton nuclear warhead in space back in 1962 just to see what would happen. (What happened is that we created a temporary radiation belt, knocked out a bunch of satellites, damaged some of the electrical and communication infrastructure in Hawaii, and caused some impressive light shows.) https://en.wikipedia.org/wiki/Starfish_Prime https://en.wikipedia.org/wiki/Starfish_Prime

by elihu 6y ago

willis936 6y ago

I generally expect sub 100 MHz to be called radio rather than microwave, but I shouldn’t make assumptions. So you need a quarter wave to be longer than a building to make it not a concern, practically it needs to be much longer if you’re sending serious power and want to keep the density down. Let’s aim for a 1 km long antenna in space with voltage high enough that ohmic losses are not a concern, or a very large superconducting antenna and all of the apparatus that goes with it. Millions of volts likes to arc when you have debris just floating around everywhere in space. Superconducting is much more attractive regardless of the extra apparatus. I don’t see many points of concern, though you could still damage infrastructure if you aren’t constantly aligned. Blowing up terrestrial grids isn’t as bad as cooking people alive. It would still be the most dangerous thing we've ever put in space by a pretty wide margin. Keep space filled exclusively with small tin cans is not an accident and not entirely due to technical or economic limitations. It is a very sensitive political area. Putting anything that could be dangerous in orbit makes it dangerous to everyone. So your adversary across the ocean blows up a reactor? Cool. As long as they don't blow me up.

elihu 6y ago
> It would still be the most dangerous thing we've ever put in space by a pretty wide margin. I don't know about that. We set off a 1.4 megaton nuclear warhead in space back in 1962 just to see what would happen. (What happened is that we created a temporary radiation belt, knocked out a bunch of satellites, damaged some of the electrical and communication infrastructure in Hawaii, and caused some impressive light shows.) https://en.wikipedia.org/wiki/Starfish_Prime https://en.wikipedia.org/wiki/Starfish_Prime